1. Field of the Invention
The present invention relates to an anti-fuse structure and a programming method thereof, and more particularly to a method of programming an anti-fuse using a laser, and electrically connecting the anti-fuse with an under bump metallurgy layer. The present invention also relates to an anti-fuse structure formed by the aforesaid method.
2. Description of the Prior Art
A fuse and an anti-fuse are electrical devices that perform opposite functions. A fuse starts with a low resistance and is designed to permanently break an electrically conductive path, whereas an anti-fuse starts with a high resistance and is designed to permanently create an electrically conductive path.
This technology is widely used in integrated circuits. For example, the fuse or the anti-fuse is often used to repair circuits or to function as a programmable link. When defects are found in a circuit, fuses can be selectively cut or anti-fuses can be selectively conducted for repairing or replacing defective circuits. Alternatively, after a semiconductor wafer is completed, data input can be performed from outside by using the fuse or anti-fuse as a programmable link. Data bits “1” or “0” can be decided by electrically conducting or cutting the fuse or the anti-fuse.
As fuses and anti-fuses are commonly used in semiconductor elements such as DRAMs, SRAMs, PROMs or FPGAs, integrating the fabricating steps of the fuse and anti-fuse with other semiconductor elements is a primary objective in the field.